1. Field of the Invention
The present Invention relates to a fluidized bed apparatus used for a granulation or coating operation of powder particulates (powder and/or particulates). In particular, it relates to a fluidized bed apparatus that allows an infinitesimal loading amount.
2. Description of the Related Art
In the field of pharmaceutical research, new synthetics in an early stage of development of medicines and the like are produced in units of grams or milligrams. These minute amounts of synthetics are not suitable for pharmaceutical research carried out with 300 g to 1000 g-load laboratory-scale fluidized bed reactors currently placed on the market since the apparatuses are too large. If an experimental evaluation is intended by charging these minute amounts of synthetics into a 300 to 1000 g-load laboratory-scale fluidized bed reactor currently placed on the market, the following problems will occur.
First, the loading amount is too small to fluidize sample powder. Second, the sample powder adheres to a container wall or a bag filter since the container is too large, so that fluidized powder will be remarkably small in amount. Third, the sample powder has an excessively large space during fluidization since the container is too large, so that adhesion of a spray liquid (such as a binder or coating liquid) sprayed from a spray nozzle to the sample powder will be remarkably reduced. Fourth, spray nozzles equipped with these laboratory-scale reactors cannot realize fluidization appropriate for granulation or coating operation since the quantity of air is too large. In addition, since the quantity of the liquid is too large relative to the minute loading amount, aggregate clusters will be instantaneously produced. Under the above conditions, currently, there is no fluidized bed apparatus that can be operated with a load in units of grams.
Moreover, the minute amounts of synthetics have been experimentally evaluated manually using mortars, beakers, and other instruments in the current situation. Accordingly, the operational conditions are unstable and problems such as human error and deficient reproducibility will occur. For these problems, comparability for next-stage laboratory-scale reactors cannot be obtained. Furthermore, currently, it is said that a few hundred billion yen is required for top-level new drug development of anticancer drugs, gene therapy agents, and the like, and it is an extremely important task to meet demand for a few gram-load fluidized bed apparatus that can satisfy conditions, such as operation with a minute loading amount, reduction of screening time, and collection of quantitative data.
On the other hand, in the field of preparation research carried out after the pharmaceutical research as in the above, it is said that new synthetics delivered to the preparation research are generally 100 g, however, it is also said that these are approximately 50 g in some cases. These minute amounts of synthetics are not suitable for pharmaceutical research carried out with 300 g to 1000 g-load laboratory-scale fluidized bed reactors currently placed on the market since the apparatuses are too large. If an experimental evaluation is intended by charging these minute amounts of synthetics into a 300 to 1000 g-load laboratory-scale fluidized bed reactor currently placed on the market, the following problems will occur.
First, the loading amount is too small to fluidize sample powder. Second, the sample powder adheres to a container wall or a bag filter since the container is too large, so that fluidized powder is remarkably small in amount. Third, the sample powder has an excessively large space during fluidization since the container is too large, so that adhesion of spray liquid (such as a binder or coating liquid) sprayed from a spray nozzle to the sample powder is remarkably reduced. Fourth, spray nozzles equipped with these laboratory-scale reactors cannot realize fluidization appropriate for granulation or coating operation since the quantity of air is too large. In addition, since the quantity of liquid is too large relative to the minute loading amount, aggregate clusters are instantaneously produced. Under the above conditions, currently, there is no fluidized bed apparatus that can be operated for usage in the preparation research including prescription research and dosage form research with a load of tens of grams.
Moreover, in the field of solid preparation of granules, fine granules, capsules, granules for tablets, the majority of drug preparation units are fluidized bed apparatuses. The reasons for this include that a single fluidized bed apparatus can carry out mixing, granulation, drying, and coating. With such a background, it is an extremely important task to meet demand for a fluidized bed apparatus capable of securing tens of gram-load as well as a superior laboratory-scale reactor.
Meanwhile, as a backdrop to preparation research, manufacturing costs of a few trillion yen per year are required to manufacture domestic top-level off-patent products, and this can be reduced by half by outsourcing. This accelerates commissioned processing. In addition, the revision of the Pharmaceutical Affairs Law permits succession of manufacturing approval, so that current commissioned products, may be manufactured by commissioned companies, and distributed by pharmaceutical companies. This makes it possible for the pharmaceutical companies to cope with enormous costs for development, and there is no doubt at the commissioned companies will take charge of preparation manufacturing in the future. In this background, it is an extremely important task to meet demand for tens of gram-load fluidized bed since it can reduce the costs for research and development and the screening time.
Patent Document 1: Japanese Published Unexamined Patent Application No. 2004-97852
Patent Document 2: Japanese Published Unexamined Patent Application No. 2004-122057